There have been many attempts in the past to devise a mechanical harvester for the picking of lowbush blueberries, particularly in the maritime provinces of Canada where there are extensive fields of the crop to be picked each year. The typical manner of blueberry picking has involved the use of a hand tool wielded by an individual picker, the tool being like a combination comb and scoop, which is moved through the berries to scrape them from the bushes and collect them in a funnel-like portion of the tool. This is back-breaking work.
Mechanical harvesters date back to the late 1960's, having been developed by individual berry farmers or by companies that see the business as a profitable one. For example, an early harvester is shown in Canadian Patent No. 961,275 of The Chisholm-Ryder Company. This harvester used a cylindrical reel having a plurality of tines spaced apart along an elongated rod, there being a plurality of such rods circumferentially spaced about the reel. The tines, as the reel rotated, were combed through the bushes so as to pull the berries therefrom and then they carried the berries upwardly until they fell therefrom into the centre of the reel. The falling berries encountered a conveyor running axially within the reel, which conveyor carried the berries laterally to another conveyor running to the rear of the harvester, from which they were deposited into a flat or other container. The Chisholm-Ryder harvester was mounted to the front of a small garden tractor and was pushed thereby through the berries. While it did work it was not particularly efficient and it did not operate satisfactorily on uneven ground.
A later development is reported in Canadian Pat. No. 1,249,727 of Bragg Lumber Company. According to the patent, this harvester mounts a picking head, almost identical to the Chisholm-Ryder head, on the side of a farm tractor, but in such a manner that the picking head is "towed " by the tractor. The arrangement ostensibly accommodates variations in the ground by allowing for pitch and roll of the head during operation. As with the Chisholm-Ryder head, the tines of the Bragg harvester are controlled by a cam and cam follower arrangement. In the Bragg harvester, as the tines approach top dead centre of the reel they are caused to flap rapidly to dislodge the berries carried thereby for easy deposit on the internal conveyor. While this harvester is an improvement over the Chisholm-Ryder harvester it still has its shortcomings. In particular, it is necessary to harvest a field in one direction only so that the tractor does not travel over bushes from which berries have not already been stripped. Otherwise the tractor wheels will crush berries in its path. In fact, the first pass of the harvester through a field will result in some loss due to crushing by the tractor wheels, unless a path is cleared first of all by manual harvesting. Only after that first pass can the tractor be driven in the proper direction to minimize loss. Also, the harvested path is limited to the width of the picking head, typically 3 to 4 feet. Many passes are required to harvest a large field. Furthermore, according to the patent, the weight of the picking head is supported only by a pair of skids mounted to the ends of the picking head. This weight is substantial and although there is the ability for the picking head to pitch and roll on uneven ground the weight thereof will tend to make the supporting skids dig into soft ground.